1. Field of the Invention
The present invention relates to a dryer, and more particularly, to a control method and system for a belt-driven clothes dryer that are able to automatically detect a breakage of a power transmission system coupled between a drum and a motor included in the dryer.
2. Discussion of the Related Art
A dryer is a device that automatically dries wet objects (e.g., clothes or shoes) by providing heated air under the control of a controller, and smarter and more efficient dryers that are able to meet the users' various requirements are in great demand. In general, a typical clothes dryer includes a tub (drum) containing the wet objects to be dried, a motor, and a power transmission system which is coupled between the motor and the drum for transmitting the power generated by the motor during a dry operation of the dryer. During the dry operation, the heated air flows into the drum and the drum continuously rotates so that the wet clothes inside of the drum could be dried. The moisturized air within the drum is continuously discharged from the drum and heated dry air flows into the drum simultaneously, while the drum rotates in the dry operation.
If there is a breakage in the power transmission system coupled between the motor and the drum, this could result very serious damages to the dryer and the objects within the drum. For example, if electric power is continuously supplied to the motor and the heater when a belt coupled between the motor and the drum for power transmission is broken, there is no motion of the drum and the objects within the drum. Therefore, the heated air will continuously make contact with same portions of the objects for a long time, and this could result serious damages to the objects. In order to substantially obviate the problems due to these limitations and disadvantages, many dryer manufactures have been trying to make clothes dryers capable of automatically detecting a breakage of the power transmission system and controlling operation of the dryer based on such breakage detection.
One of the examples of the existing breakage-detectable clothes dryers includes a mechanical breakage detection assembly including an arm which mechanically moves when the belt provided between the motor and the drum is broken, and a switch which automatically shuts off the power supply to the motor based on the motion of the arm. However, this detection assembly requires a complicated mechanical structure. For example, the arm must be provided at a predefined location within the dryer so as to accurately detect the breakage of the belt, and this could create a serious structural limitation when manufacturing the dryer. In addition, a slight dislocation of the switch which operates due to the rotation of the arm could result malfunction of the breakage detection assembly. Therefore, there are great necessities for a control system and method for a clothes dryer, which are able to detect the breakage of the power transmission system without requiring any complicate mechanical system.